Radio antenna circuit



Oct. 16, 1934. p K (5|DDENS 1,977,271 I RADIO ANTENNA CIRCUIT Filed March 2, 1 953 5 W x N I IN VENTOR B Y 5 MW? eJJ WWI/2m .7 61 A TTORNEY Patented Oct. 16, 1934 UNITE-D STATES 1,977,271 nAmo ANTENNA cmom'r Paul K. Giddens, Kansas City, Mo., assignor of fifty-one per cent to Nelson E. Johnson, Kansas City, Mo.

Application March 2, 1933, Serial-No. 659,260

3 Claims. (o 250-33) My invention relates to improvements in radio antenna circuits.

The object of my invention is to provide a novel antenna circuit adapted for use with, or as a part of, a usual radio receiving set, which circuit is simple, greatly improves the selectivity and tonal qualities of the set, largely increases the strength of the signals given out, which provides a substantially constant voltage output, and

'. which is eflicient for use with widely varying frequencies and wave lengths.

The novel features of my invention are hereinafter fully described and claimed.

This application is a continuation in part of an application for Radio antenna systems, filed by me June 23, 1930, having Serial Number 463,090, and an application for Radio receiving systems, filed by me May 19, 1932, having Serial Number 612,244.

The novel features of my invention are hereinafter fully described and claimed.

In the accompanying drawing, which illustrates my invention,

Fig. 1 is a diagrammatic view of a circuit embodying one form of my invention.

Fig. 2 is a diagrammatic View of a circuit embodying another form of my invention.

Similar characters of reference designate similar parts in the different views.

Referring to Figs. 1 and 2, 1 designates theusual antenna connected by an antenna connection, comprising a conductor 2, with an element comprising a conductor, which, as shown is a primary winding 3. An element comprising a conductor, which, as shown, is a secondary winding 4 is inductively related to the winding 3.

The lower, or low potential end portion of the secondary winding 4 is, preferably, grounded by means of a conductor 5.

An element comprising a capacity coupling consisting, as shown, of a condenser 6, preferably of variable type, a conductor '7 connected to one terminal of said condenser, and a conductor 8 connected to the other terminal of the condenser 6, connects one end of the primary winding 3 with the high potential end portion, the upper end portion, as shown, of the secondary winding 4.

In the form shown in Fig. 1, the conductor 7 is connected to the lower or low potential end of the primary winding 3, while in the form shown in Fig. 2, the conductor '7 is connected to the upper or high potential end of the primary winding 3. In both forms, the conductor 8 is connected to the high potential end portion of the secondary winding 4.

'An element comprising a capacity coupling consisting of a condenser 9, preferably variable, as shown, a conductor 10 connected to one terminal of the condenser 9 and to the conductor 8, and a conductor 11 connected to the other ter- Q0; minal of the condenser 9 and to the ground conductor 5, is shunted across the secondary winding 9.

In the form shown in Fig. 1, an output connection 12 is conductively connected to the aerial connection 2 and is conductively related to the condenser 6 through the primary winding 3 and the conductor 7.

In the form shown in Fig. 2, the lower end of the primary winding 3 is free.

In Fig. 2 an output connection comprising a conductor 13 is conductively related to thecondenser 6 and to the high potential portion of the secondary winding 4 by being directly connected to the conductor 8.

Connecting the primary winding 3 in series with the secondary winding 4, by means of the variable capacity coupling 6, permits tuning the primary circuit to different desired radio frequencies, and the transfer of such frequencies at a substantially constant voltage to the output connection, by increasing the voltage at the lower frequencies and decreasing it at the higher frequencies.

Connecting one end only of the non-grounded primary winding 3 with the secondary winding 4, and by making that connection with the variable capacity coupling 6, permits of a maximum transfer of energy to. the output connection, and loss of energy to ground prevented.

By shunting the variable capacity 9 across the secondary winding 4, the secondary circuit thus formed may be made to resonate at the same frequencies as the primary circuit, thus building up the tuned voltage, setting up a high rejection to the untuned voltage and greatly increasing selectivity.

Shunt tuning of the secondary winding 4 by means of the variable capacity coupling 9, in conjunction with the tuning of the antenna circuit by means of the variable capacity coupling 6, permits of alining or tracking when the antenna circuit is used in-- connection with sueceeding shunt tuned circuits, thus enabling the use of a single tuning control of the multiple tuned circuits.

I do not limit my invention to the specific, structures shown and described, as many modifications, within the scope of the appended claims may be made without departing from the spirit of my invention.

What I claim is:-

1. In a radio antenna circuit, an aerial conductor, a primary inductance connected at one end to said aerial conductor, a secondary inductance inductively related to said primary inductance, said end only of said primary inductance being connected to said secondary inductance, a capacity coupling connecting said end with the high potential portion of said secondary inductance, a variable: capacity coupling shunted across said secondary inductance, and an output conductor connected to said first named coupling.

2. In a radio antenna circuit, an aerial conductor, a primary inductance connected at one end to said aerial conductor, a secondary inductance inductively related to said primary inductance, said end only of said primary inductance being connected to said secondary inductance, a capacity coupling connecting said end with the high potential portion of said secondary inductance, a variable capacity coupling shunted across said secondary inductance, and an output conductor connected to said second named coupling.

3. In a radio antenna circuit, an aerial conductor, a primary inductance connected at one end to said aerial conductor, a secondary inductance inductively related to said primary inductance, said end only of said primary inductance being connected to said secondary inductance, a variable capacity coupling connecting said end with the high potential portion of said secondary inductance, a variable capacity coupling shunted across said secondary inductance, and an output conductor connected to the high potential portion of said secondary inductance.

PAUL K. GIDDENS. 

